and Vegetation of Sicily. 111 
are the ruins of ‘Taormina, consists of a compact limestone 
resting on the mica slate, which stretches far into the interior, 
and constitutes a sort of boundary between the volcanic and 
Neptunian districts, a barrier beyond which the lavas of Etna 
have never yet penetrated. 
We will now briefly describe the several formations of these 
three parts or divisions. 
The granitic rocks of the Pelorian chain contain also em- 
bedded masses ofa mixture of quartz and hornblende. They 
extend uninterruptedly as far as Melazzo. The peninsula on 
which the castle and town have been built is composed of 
well-marked gneiss, upon which there rests a compact greyish 
limestone containing fossil remains. This Dr. Daubeny con- 
jectures to be of a recent origm. At Cape Minjivio (Mons 
Jovis), the mica slate alternates with a bluish crystalline lime- 
stone without shells, a granular rock, consisting principally of 
quantz and mica, w che the author names quar tay rock, and a 
sandstone made up of minute fragments of the above two in- 
eredients. The red sandstone which succeeds the slate form- 
ation is not micaceous, but contains red iron-shot grains of 
sand. This continues to Cefalu, except in places where it is 
interrupted by a bed or two of compact greyish limestone 
without petrifactions. The bold promontory ofCefalti consists 
of a bluish fetid limestone (called a Lumachella marble), 
and possessing organic remains. ‘This formation, which rests 
upon the sandstone, extends to Trapani, including the Nebro- 
densian and Palermitan mountains. It contains magnesia. 
But the valleys and coast between Cefalu and ‘Termini, 
about Palermo and Castell’ a mare, are covered with a coarse 
pudding-stone, containing fragments of quartz, and of the 
magnesian limestone on which it rests, or of a calcareous 
breccia, in which sand is also present, and many fossils. ‘The 
line of demarcation between this, and the older calcareous 
formation, is very distinctly marked by the character of vege- 
tation. The compact limestone like that of the Apennines, 
or of Nismes * is chiefly adapted for the olive, and affords but 
a scanty pasturage, vegetation being obstructed by the frag- 
ments of chert; whereas the breccia affords the finest crops 
. * To compare the geological structure of Sicily with that of the island 
of Sardinia, see Mémoire Géologique sur VP Isle de Sardaigne par M, de la 
Marmora, in the 11th volume of Mémoires du Museum @ Histoire Naturelle, 
Where it appears that the east side, comprehending nearly one half of the 
island, is of primitive and transition rocks, consisting of granite, porphyry, 
and mica slate; the west side is composed of calcareous strata of the 
tertiary class, where volcanic rocks principally occur ; and there is seen in 
some places a secondary limestone, which probably ‘corresponds with that 
of the Palermitan and Madonian mountains. 
